In a vehicle, a storage battery such as a lead accumulator, a nickel-hydrogen cell, or a lithium ion cell is loaded and power necessary for a hybrid automobile or an electric automobile such as power supply to an engine starting motor or electrical units is supplied from these storage batteries.
Storage batteries aiming at power supply during traveling which are loaded in a hybrid automobile are generally composed of multi-series and multi-parallel. The state of charge (SOC) and state of health (SOH) of these batteries, input/output allowable current and power, and abnormal state are detected in real time and the controller of the vehicle, according to the detected state of the storage batteries, uses the power of the storage batteries. When an abnormality occurs in the storage batteries, the vehicle is controlled so as to be stopped and there is a possibility that the function as an automobile may be deteriorated extremely. Therefore, a fail-safe function according to the abnormality of the batteries is necessary.
To solve such a problem, in Japanese Patent Laid-open No. 2004-6138, a fail-safe method for separating a faulty set battery unit by a switch among a plurality of set battery units connected in parallel and restricting the maximum output of a motor according to the number of sound set battery units is proposed.